Test plug for fluid systems



April 21, 1964 J. F. MOORE TEST PLUG FOR FLUID SYSTEMS Filed April 6,1962 R m E mu ....W.H.....: N o mw h. M F W W o J M ATTOR NEYT:

United States Patent 3,129,726 TEST PLUG FOR FLUED SYSTEMS John F.Moore, Drawer M, Kermit, Tex. Filed Apr. 6, 1962, Ser. No. 185,684 3Claims. (ill. 13890) This invention relates to test apparatus associatedwith pipe system, and in particular to a plug for sealing off an openend of an incomplete pipe line, as in a sewer system. In connection withsuch operations, it becomes necessary, from time to time, to seal offthe casing temporarily, to test for leaks in the system. The nature ofthis work requires a closure means which is rapid and certain inoperation, with corresponding facility of operation, and it is aprincipal object of the present invention to attain these ends in a moresatisfactory manner than heretofore known. Cost of equipment is also animportant factor, and it is therefore a further object to provide aclosure plug which is low in cost, easy of manufacture, and adapted forrepeated use. A still further object is to provide a closure plug whichavoids the need for mechanical mounting means and special tools, yet isoperable through readily available equipment. Yet another object is toprovide a pneumatic plug which is operable under relatively lowpressure.

These and other ends, which will be readily apparent, are attained bythe present invention, a preferred form of which is described in thefollowing specification, as illustrated in the drawing, in which:

FIGURE 1 is a perspective view of the plug, mounted in an end opening ofa sewer pipe line,

FIGURE 2 is an axial, sectional view, enlarged, taken on the plane ofthe line 2-2 in FIGURE 1,

FIGURE 3 is an elevational view of the plug, apart from the well casing,uninfiated, and broken away, in part, and

FIGURE 4 is a transverse sectional view through the uninfiated plug,taken on the plane of the line 44 in FIGURE 3.

Referring to the drawing by characters of reference, there is shown, inFIGURES 1 and 2, a sewer pipe 10, laid in a trench 11, the ground levelbeing indicated at 12. The pipe 10 is elbowed at one end, and receives avertical pipe section 13.

The end opening of the pipe 10 is sealed off by a pneumatically operableplug, indicated as a whole by the numeral 14, and comprising four parts,namely, a head 16, a bag 18, a clamp 20, and a valve nipple 22. The bag18, preferably formed from an oil-resistant synthetic rubber, is ofcylindrical, tubular form, of substantial wall thickness, and having anopen top end, and a closed, rounded, bottom 24. The open upper end ofbag 18 is received on a reduced neck 26 of the cylindrical head 16, andis securely clamped in place thereon by means of the metal clamp strap20, which carries a clip 30 on one end, adapted to be crimped over theother end of the band, after the band has been drawn sufliciently tocompress the wall of the bag inwardly, to render the connectionpressure-proof.

The head 16 has a through, axial bore 32, for passage of air underpressure into the bag, and the bore is threaded at its upper end, toreceive the conventional valve nipple, 22, having a valve core 34,similar to the fittings on pneumatic tires and tubes.

In use, the bag is held in the opening of pipe 10, and the end fixture36 of an air line 38 placed over the nipple 22, which results inpressurizing of bag 18, and its close and firm engagement with the innerwall of the pipe, even with pressures as low as 3 to p.s.i., resultingnot only in an effective seal against fluid pressure in the casing, butalso in a frictional engagement over a large area, which resistsmovement of the bag out of the casing.

With the closure plug in place, the system is tested for leaks byintroducing Water into the pipe, as shown in FIG- URE 1, wherein thewater level is indicated at 38, the available test pressure dependingupon the head of water, and therefore on the height of Vertical pipesection 13. Removal of the closure plug, when such is desired, is easilyeffected by pressing on the valve core stem, as in the case of deflatinga tire, after which the limp bag is easily lifted out of the pipe. Thedevice will fit a variety of pipe bores, and since there are nointerengaging parts, wear and breakage are reduced to a minimum, and thedevice is adapted for repeated use, over a long period.

In lieu of pneumatic pressure, hydraulic pressure may be employed, usinga suitable form of valve for the purpose.

While the device has been illustrated as a test apparatus for a sewerpipe system it obviously has utility in other environments, as forinstance in sealing off oil well casrngs.

While a certain, preferred embodiment has been shown, variousmodifications will be apparent, in the light of this disclosure, and theinvention should not, therefore, be deemed as limited, except insofar asshall appear from the spirit and scope of the appended claims.

I claim:

1. A closure plug for the pressure testing of fluid systems, comprisinga cylindrical plug with a reduced neck on one end, and having an axialbore, a nipple with a pneumatic valve threaded in said bore on the endof the head opposite said neck, a tubular bag made of rubbery material,of uniform diameter, and having a rounded, closed bottom, and an openend having said uniform diameter received on said neck, a metal strapsurrounding said bag in the region of said neck, and means securing saidstrap in ring form in compressing relation to said bag.

2. A closure plug for the pressure testing of fluid systems, comprisinga cylindrical plug with a reduced neck on one end, and having an axialbore, a nipple with a pneumatic valve threaded in said bore on the endof the head opposite said neck, a tubular bag made of rubbery materialof substantially uniform diameter, and having a rounded, closed bottom,and an open end having said uniform diameter received on said neck, ametal strap surrounding said bag in the region of said neck, and meanssecuring said strap in ring form in compressing relation to said bag.

3. A closure plug for the pressure testing of fluid sys tems, comprisinga plug with a cylindrical neck on one end, and having a through bore, anipple with a fluid valve secured in said bore on the end of the headopposite said neck, a bag made of flexible material of substantiallyuniform diameter, and having a closed bottom, and an open end havingsaid uniform diameter received on said neck, and means securing said bagto said neck in fluid sealing relationship.

References Cited in the file of this patent UNITED STATES PATENTS1,498,294 Preston June 17, 1924 1,906,151 Goodman Apr. 25, 19331,946,138 Gardner Feb. 6, 1934 2,493,452 Grigg Jan. 3, 1950 2,672,160Wrabel Mar. 16, 1954 2,678,666 Theis et a1. May 18, 1954 2,723,040Merelle Nov. 8, 1955 2,857,933 Lithun Oct. 28, 1958 FOREIGN PATENTS22,591 Great Britain Dec. 17, 1898

1. A CLOSURE PLUG FOR THE PRESSURE TESTING OF FLUID SYSTEMS, COMPRISINGA CYLINDRICAL PLUG WITH A REDUCED NECK ON ONE END, AND HAVING AN AXIALBORE, A NIPPLE WITH A PNEUMATIC VALVE THREADED IN SAID BORE ON THE ENDOF THE HEAD OPPOSITE SAID NECK, A TUBULAR BAG MADE OF RUBBERY MATERIAL,OF UNIFORM DIAMETER, AND HAVING A ROUNDED, CLOSED BOTTOM, AND AN OPENEND HAVING SAID UNIFORM DIAMETER RECEIVED ON SAID NECK, A METAL STRAPSURROUNDING SAID BAG IN THE REGION OF SAID NECK, AND MEANS SECURING SAIDSTRAP IN RING FORM IN COMPRESSING RELATION TO SAID BAG.